I remember - many moons ago - debugging a plugin that I was building for a very, very, long time. The only thing that fixed my issue (which I can't remember for the life of me), was to name the plugins main file (the one with the plugin header) the exact same name as the plugins folder.

Since then, I have never named the plugin file anything other than the name of the folder. Is this necessary for any core functionality to work, or am I just being superstitious?